BSCP31 Trading Unit Application for West Burton A&B Power Stations

Transcription

1 Attachment 1 BSCP31 Trading Unit Application for West Burton A&B Power Stations Full description of nominated BM Unit(s) (in conjunction with form BSCP31/4.5) West Burton A Power Station comprises: Plant 4 x 500MW coal fired steam generating units, each with an associated 50MVA 22/11kV unit transformer connected to 11kV unit boards within the station and a 600MVA 22/400kV generator transformer connected to transmission at NGET s West Burton 400kV substation busbars. 2 x 20MW gas turbine generators, one connected within the station to the 11kV unit boards for main generating unit 1, the other connected within the station to the 11kV unit board for main generating unit 4. 2 x 50MVA station transformers connected to the 132kV busbars at NGET s 132kV West Burton substation, which is fed via 400/132kV Grid Supply Transformers from the adjacent 400kV substation (see Attachment 2 map and Attachment 3 NGET line diagram). BMUs The net flow to the transmission system for each main generator/unit transformer pair (T_WBUPS 1, T_WBUPS 2, T_WBUPS 3, T_WBUPS 4) and for each gas turbine generator (T_WBUGT 1, WBUGT 4) is represented as a transmission connected BM Unit. The main generator/unit transformer pairs have transmission Connection Entry Capacity (CEC) 503 MW each. The GT generators 1 and 4 have CEC 20 MW each, and share connection with main generators 1 and 4 respectively (see Attachment 4 Extract from West Burton A Connection Agreement). The aggregated metered station demand from the 132kV substation busbars is represented as a single embedded station demand BM Unit (E_WBUPS STX), since it is connected at 132kV. The 7 BMUs at West Burton A are included in existing Class 1 Trading Unit West Burton Power Station V2. This would be de registered if (and only if) the proposed combined West Burton Power Stations A&B Trading Unit becomes effective. Settlement Active Energy Metering & BMU Meter Aggregations The active energy metering equipment is compliant with Code of Practice E in effect at the time of installation (allowing metering on the low voltage side of grid transformers, with compensation to the high Page 1 of 6

2 voltage transmission boundary). Lifetime meter dispensation D/472 allows use of protection rated current transformers for reactive measurements for generator unit 3, rather than measurement rated current transformers. Settlement active energy meters for each main generator and for its associated unit transformer are located on the low voltage 22kV side of each generator transformer. The auxiliary Gas Turbine connections to the Unit Boards are metered at 11kV. Settlement metering for the gas turbine generator 1 connected to unit board 1 is used to determine its BM Unit metered volume, and is subtracted in aggregation rules from the boundary flow for main generator and unit transformer 1 to give the main generator/unit 1 BM Unit volume. Similarly, settlement metering for the gas turbine generator 4 connected to unit board 4 is subtracted from the boundary flow for the BM Unit representing main generator 4 and unit transformer 4. Ie. T_WBUPS 1 (coal/unit) = Unit 1 transmission boundary flow auxiliary gas turbine 1 flow. T_WBUPS 4 (coal/unit) = Unit 4 transmission boundary flow auxiliary gas turbine 4 flow. Settlement active energy metering for the station load is located on the Low Voltage 11kV side of the station transformers, with compensation to the 132kV high voltage side. West Burton B Power Station comprises: Plant 3 x CCGT Units, each comprising a 388 MVA gas turbine generator with 390 MVA 400/17kV power transformer and a 200 MVA steam turbine generator with 200 MVA 400/15 kv power transformer. The CCGT Units operate at less than the maximum theoretical capacity. All 6 power transformers are connected to EDF Energy s 400kV banking compound busbars within the West Burton power station site, from which two 400kV cables run to NGET s 400kV busbars at NGET s 400kV substation situated at the West Burton site. Units 1 and 3 each have a 22/6.6kV unit transformer connected to respective 6.6kV unit boards within the station. Unit 1 is normally used to provide power to the unit boards for main Unit 2, which does not have its own unit transformer. There are no separate station transformers, and no other connections to the transmission or distribution total system. A +/ 50 MW battery system comprising 10 x 5 MW sub modules is situated within the West Burton B site. Part of the system is connected to the main CCGT unit 1 6.6kV boards, and the remainder to the main CCGT unit 3 6.6kV unit boards within the station. Two of the battery sub modules can switch between the unit 1 and unit 3 boards, with normal configuration giving +/ 20 MW capability through unit 1 and remaining +/ 30 MW capability through unit 3. Page 2 of 6

3 BM Units The 3 CCGT Modules are each represented as a BM Unit. Each has a transmission Connection Entry Capacity 470 MW (Attachment 5). The battery is operated as a single controllable entity, but an approved non standard BM Unit arrangement (ISG198/02) is in effect until 31 December 2021 to represent it as two BM Units, as requested by NGET due to its connection to transmission via two separate circuits. Its combined transmission CEC is 50 MW. Its two separate settlement metered connections within the station are each represented as a BM Unit (T_WBURB 41 and T_WBURB 43). EDF Energy will consider how best to address the ongoing battery BM Unit configuration before the current permission for a non standard configuration expires (31Dec2021). The Trading Unit composition will be revisited at that time if appropriate, for example if the current battery BM Units were to be consolidated or sub divided. The 3 CCGT Module BMUs at West Burton B are included in existing Class 1 Trading Unit West Burton B CCGT. This would be de registered if (and only if) the proposed combined West Burton Power Stations A&B Trading Unit becomes effective. Settlement Metering & BMU Meter Aggregations CoP1 settlement meters are situated on the high voltage side of the six generator transformers connected to EDF Energy s 400kV banking compound busbars, in accordance with CoP1 at the time of construction. The 400kV banking compound busbars are connected by two 400kV cable circuits to NGET s 400kV substation busbars. CoP1 meters are located on the two 6.6kV circuits within the site connecting the two sides of the battery system to the main CCGT unit 1 and unit 3 boards. Lifetime meter dispensation D/478 permits battery meters at lower voltage within the site, with compensation to the HV side of the 400kV transformers. CCGT module 1 and 3 BM Unit (T_WBURB 1 and T_WBURB 3) aggregation rules subtract the relevant battery BM Unit meter readings from the boundary metering to represent the relevant CCGT module. CCGT module 2 BM Unit (T_WBURB 2) is not connected to the low voltage system within the site, and is aggregated from its 400kV boundary meters alone. Ie. T_WBURB 1 (CCGT) = unit 1 boundary flow battery unit 41 flow T_WBURB 3 (CCGT) = unit 3 boundary flow battery unit 43 flow Confirmation from each Lead Party of their intention to be associated with a single Trading Unit The applicant, EDF Energy (Thermal Generation) Ltd, is the registrant for all the BM Units. Confirmation of its agreement for the Trading Unit is attached (attachment 6). Page 3 of 6

4 Full description of Metering Systems See the description of metering given within Full description of nominated BM Unit(s) above. BSCP20 registration forms have not been included, but can be provided on request. Full description of points of measurement of electrical flow See the description of metering given earlier within Full description of nominated BM Unit(s). Line diagrams showing electrical connections and energy flows at nominated BM Unit(s) Attachment 7 is a simple line diagram showing the plant, electrical connections, BM Units, settlement metering locations and typical flow directions at the West Burton Power Stations. The actual flows vary according to which items of plant are operating. Line diagrams showing location of Metering Systems Attachment 7 is a simple line diagram showing the plant, electrical connections, BM Units, settlement metering locations and typical flow directions at the West Burton Power Stations. Evidence that assets & equipment are capable of transmitting or distributing the quantity of Electricity to be transmitted or distributed at the nominated BM Unit(s) See extracts from NGET Bilateral Connection Agreements, attachments 4 (WBA) and 5 (WBB). Confirmation from the Transmission Company that the metering arrangements are compatible To be confirmed. Supporting evidence from associated BSC Parties (as appropriate) All the BM Units are registered to EDF Energy (Thermal Generation) Ltd. The only other directly associated BSC Parties are National Grid, and Western Power Distribution (WPD) who have separate distribution feeds from the 132kV substation. WPD take power from the 132kV busbar at the National Grid substation, from which West Burton A station demand is also taken (and may be used as part of a difference metering arrangement for the East Midlands _B GSP Group). This is not directly relevant to the Trading Unit status of the West Burton BM Units. Class 2 only Evidence of Dedicated Assets Not applicable. Page 4 of 6

5 Class 3 only Evidence of Contiguous Assets Not applicable. Class 6 only Other evidence having regard to the criteria set out in BSC The arrangement is equivalent to a Class 1(B) Trading Unit as in the BSCP31 line diagram (pasted below) in all respects except that there are two power stations and the auxiliary generating units at West Burton A and the battery BM Units at West Burton B are connected to the respective unit/station boards. This is a normal configuration at many existing large power station Trading Units. We think the arrangement should be a Class 1 Trading Unit, but it could be a Class 6 Trading Unit if the line diagram arrangement (attachment 7) is considered materially different from that in the BSCP31 line diagram (pasted below). Page 5 of 6

6 Attachments 1 This document, supporting evidence for BSCP31 Trading Unit Application for West Burton A&B Power Stations 2 Map of West Burton site showing National Grid assets. 3 NGET West Burton Substation Assets Diagram (from West Burton B Connection Agreement) 4 Extract from West Burton A NGET Connection Agreements showing entry capacities. 5 Extract from West Burton B NGET Connection Agreement showing entry capacities. 6 EDF Energy (Thermal Generation) Ltd director s confirmation of Trading Unit application. 7 Simple Line diagram showing the plant, electrical connections, BM Units, settlement metering locations and typical flow directions at the West Burton Power Stations. Page 6 of 6